

#include <iostream>
#include <string>
#include <unistd.h>
#include <pthread.h>


const int num = 5;
pthread_mutex_t gmutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t gcond = PTHREAD_COND_INITIALIZER;


void* Wait(void* args)
{
    std::string name = static_cast<const char*>(args);
    while (true)
    {
        pthread_mutex_lock(&gmutex);
        pthread_cond_wait(&gcond, &gmutex); // 这里就是线程等待的位置 
        // 保证打印不重叠 
        usleep(10000);
        std::cout << "I am " << name << std::endl;
        pthread_mutex_unlock(&gmutex);
        // usleep(500000);
    }
}


int main()
{
    pthread_t threads[num];
    for (int i = 0; i < num; ++i)
    {
        char* name = new char[1024];
        snprintf(name, 1024, "thread-%d", i + 1);
        pthread_create(threads + i, nullptr, Wait, (void*)name);
        usleep(10000);
    }

    sleep(1);
    // 主线程依次唤醒其他线程 
    while (true)
    {
        pthread_cond_broadcast(&gcond);
        // pthread_cond_signal(&gcond);
        std::cout << "唤醒一个线程..." << std::endl;
        sleep(2);
    }
    

    for (int i = 0; i < num; ++i)
    {
        pthread_join(threads[i], nullptr);
    }
    return 0;
}

